1. Field of the Invention
The present invention relates to a fuel pump module for vehicles, and more particularly to a fuel pump module that provides an engine with ethanol fuel stored in a fuel tank.
2. Description of Related Art
In recent years, studies on fuel systems using a fuel pump for pumping ethanol fuel as a bio-energy source have increased in correspondence with the tendency toward environmentally friendly and less expensive fuels.
In foreign countries, ethanol fuel vehicles that meet legal regulations and that are environmentally friendly are being sold, and sale volumes are increasing.
However, such an ethanol fuel vehicle using ethanol fuel has a problem in that startability thereof is deteriorated because of low volatility, which is a characteristic of ethanol fuel.
In order to improve this problem, ethanol fuel vehicles employ gasoline from an auxiliary fuel tank during start-up.
In a fuel supply system of an ethanol fuel vehicle according to the prior art as shown FIG. 1, firstly, a fuel pump module is disposed to a fuel tank 101 for provide an engine with ethanol fuel.
The fuel pump module 103 is communicated to the engine 105 through a fuel hose 107 and to a canister that collects fuel evaporation gas that is recirculated to an intake pipe of the engine 105 through the fuel tank 101.
The canister 109 is communicated to an auxiliary fuel tank 111 that is filled with gasoline fuel, and the auxiliary fuel tank 111 is connected to the engine 105 in the engine compartment so as to improve startability of ethanol fuel vehicles.
Thus, during start-up of an ethanol fuel vehicle, gasoline is supplied from the auxiliary fuel tank 111 so as to operate the engine 105, and after the start-up of the engine 105, the ethanol fuel of fuel the fuel tank 101 is supplied by the fuel pump module 103 so as to operate the engine 101.
However, because a fuel pump module according to the prior art merely provides the engine with ethanol fuel in the fuel tank, it is necessary to install the auxiliary fuel tank in the engine compartment to improve deterioration of start-up that is caused by low vapor-pressure. However, this increases complexity of design of the inside of the engine compartment, and causes an increase in cost because of the manufacturing of the auxiliary fuel tank.
Further, a leak of fuel caused by collision between vehicles may occur, and frequent fuel-supply is required because the auxiliary fuel tank is too small.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.